Senyu.

One day, a colossal hole abruptly opens in the world, unleashing demons upon the land. The king believes this ominous event signals the return of the Demon King Rukimedesu, who was sealed away a thousand years earlier by the hero Kureashion. In response, the king orders the descendants of that legendary hero to confront the looming threat, and 75 people answer the call. Among them, Hero No. 45, Aruba, joins forces with Ross, a sadistic palace warrior, and their adventure begins.